Knock-off for board drop hammers and the like



Nov. 24, 1931.

H. TERHUNE Filed May 25.,

KNOCK- OFF FOR BOARD DROP HAMMERS AND THE LIKE 2 Sheets-Sheet l Nov.24, 1931. H. TERHUNE KNOCK-OFF FOR BOARD DROP' HAMMERS AND THE LIKE Filed May 23, 1929 2 Sheets-Sheet 2 Patented Nov. 24, 1931 UNITED :STA-

ESY T OFFICE HOWARD TERHUNE, or QHAMBERSBURG, PENNSYLVANIA, vAssrsnon TO-CHAMBERS- BUBG ENGINEERING COMPANY, or .CHAMBERSBUBG, PENNSYLVANIA, Anemone- T ION OF PENNSYLVANIA KNOCK-OFF FOR BOARD DROP HAMMERS -AND'LTHE LIKE Application and May 123, 1929.? Serial No.'365,491.

I have invented an improved drop hammer, and, more especially, adrop ham-merzof the kind designated as board drop hammers.

In a device oat this character, the hammer is elevated by means of comprising feed roll-s which engage and release a suitable part, so that the hammer can be lifted and dropped in succession. An object. of the invention is to reduce friction and wear to a uninimum rand, at the same time, provide a conwith respect to the ram ;-.the. cushioning'means acting upon the front trod as the latter ia'lls when the downward movement ozfithe hammer is comp'letechso that the rod carriesthe feed rolls easily and safely into position to raise the hammer for its next stroke.

An additional object of the invention is to provide a board'drop hammer havingparts arrangedto enable the steps in the operation of the hammer to be properly timed; so that the power for lifting the hammer can be brought into play at the exact :insta-nt required, without Waste of energy and loss of motion.

A further object ofthe invention is the provision in a board drop hammer o f a front rod arrangement eliminating; insofar as possible, the destructive hammering between the rod and its several seats which hold iti-n its ra sed and lowered position.

A still furtherobiect of the invention is the provision of a front rod mounting for 'hammersof this type which will permit ready adjustment, or movable and substitution, of :the stop-engaging element of the rod.

The nature andadvantagesoftheinvention are fully set forth in the following description, taken in connection with the drawings,

closed, however, is intended by way of" illustration only, and I reservethe right to snake changes in the shape, size and relative .ar-

r'angemenlt of't'he various members, ino'tnece'ssarily ISlF-IOWD. herein but nevertheless-coming within the principle ofthe-invention and embraced within the scope and meaning of the appendedclaims.

On the drawings 7 Fig. 1 1s a frontview of the 'b'oarddrop hammer according to my invention;

Fig. 2 is a side view of the, same;

Fig.1.?) is a sectional View on the line 8 3 ofFigQlgand Fig. 4 is a front view of the parts shown in Fig. 1. r t

On the drawings, the same numerals identify the same parts throughout. a

Inset-he numeral 1 to indicate the anvil of aboard idrop hammer, secured upon a .suitable bed or base, between the lower ends of side frames-2; which are in upright position. Upon the tops of these frames is the housing 3 in which are mounted the feed .aIOljlS 4. These rolls operate :to engage and disengage the board 5; whichmovesup .and down 'between the rolls 4 and is secured at its lower end :to awhammeror ram 6. Thiisram travels and down between the side framesQ and is engaged by suitable vertical guides- 7; which may have the form of ribs and areasceivedin grooves inthe sides of the hammer6. 1n =practice, the rolls 4 are so mountedand operated that whenthey are moved intocontact with opposite facesozf the board =5. and rotated, the -board is impelled upward to lift the hammer; and when the rolls 4 are .moved apart, so that they .no longer frictionalgly .engage with the board .5, the hammer-can tall,

drawingthe board 5 down with it. -Suitable pulleys are usually employed to, turn the rolls 4; and at 8 is indicated the front rod; which extends from a pivotal connection 8-- a therefor at the top of the housing 3 down along the front of the machine and is so connected at its upperend that, when the rod is lifted, the rolls 41are caused to disengage the board 5 to permit the hammer to drop; and

- VVhen the rod 8 is in its uppermost position,

a seat 12 rests upon this roller, this seat being 3 carried by a dog 13 yieldably supported from clamp 14; and yieldably secured thereto, both the dog and the clamp encircling the rod 8. The clamp 14 is made fast on the rod, but the dog 13 can move to some extent on the rod 8. The connection between the dog 13 and clamp 14 comprises headed studs 15 secured toone thereof and slidably directed through the other thereof. Surrounding these studs, between the clamp and dog, are springs 17 which yieldably maintain the dog and clamp in spaced relation. The clamp is illustrated as provided'with sockets 16 receiving the upper ends of these springs. The dog 13 can, therefore, move on the rod 8 as far as the springs 17 permit. the clamp 14 can be loosened and its position on the rod 8 adjusted as desired.

Aflixed to the rod 8 above the clamp 14 is a knock-off dog 19 having clamping engagement with the rod 8 so that it can be adjusted andsecured in desired position. This dog extends towards the path of movement of the hammer 6 which has a cam project-ion 20. In the downward movement of the ram 6, the cam projection 20 will engage the knock-off dog 19 and push the rod 8 outward from the front of the adjacent side frame 2, caus ing the seat12 to clear the roller 11 and enabling the rod to drop.

Below the roller 11 is a yoke 21 receiving the lower end of the rod 8 between the arms thereof and carrying a grooved roller 22 mounted upon a removable pin 23. The rod 8 moves between the roller 22 and the bottom of the yoke. In line with the yoke, the adjacent side frame 2 hasa channel 24 through which passes the shank 25 of the yoke, the channel being enlarged at its oppositejend on the rear of the side frame 2, as shown at 26, to provide a shoulder 27. In the enlarged part 26 of the channel is a spring 28 abutting,

the shoulder 27 and the adjacent end of the shank 25 is threaded to receive a stop nut 29. When the rod 8 moves away from the adj acent side'frame 2 to make the pin 12 clear the roller 11, it can exert a thrust uponthe roller 22 and pull the yoke 21 out to some extent against the force of the spring 28.

- On a suitable shoulder adjacent the roller 11, the side frame 2 adjacent the rod '8 carries a cushioning pad or stop made of several Of course,-

layers of leather or the like, this pad being held in place by a pin 31; and the seat 12 of the dog 13 when the rod is dropped far enough, will strike this leather cushion and be arrested thereby. At this time, the-rod 8 may move a little further; the springs 17 yielding to permit the separation of the clamp 14 and the dog 13. v

To cause the rod 8 to be lifted, I mount on the rod, adjacent the upper limit of movement of the hammer 6, an arm 33 upon a pivot 34 carried by. a clamp 35, which can be adjustably secured to the rod 8. of this arm 33 projects across the inner edge of the adjacent side frame; and the opposite end 36, which may be rounded, extends into a recess 37 of a fixed bearing block 38. The hammer 6 has a projection or stud 39 to engage the lower side of the arm 33 and lift it.

The block 38 is secured in the adjacent side 7 frame 2 by bolts 40 and suitable means may be provided for enabling this block, to be raised or lowered and secured by the bolts 40 in adjusted position.

The machine is also provided with a treadle 41 at the front below the anvil 1; the treadle being mounted on a shaft 42 which carries an arm 43, attached to a link44which runs up to the top of the machine and is there connected to one or more suitable arms indicated at 45 to which control clamps',no't shown, normally acting to engage the board 5 and keep the board in its elevated position. Whenever the treadle 41 is depressed, these clamps are withdrawn and the board 5 released for regular operation. Such clamps are well-known to those acquainted with this artand need not be further illustrated or further described herein.

In operation, whenever the hammer is to be used, the treadle 41 must be first depressed to release the board 5. Then, if the hammer has been lifted high enough for the projection 39 tomove up the arm. 33, thus lifting the rod 8 to disengage the rolls 4 from the board 5, the hammer 6 at once drops. At this time, the rod occupies the position shown particularly in Fig. 3. hen the hammer reaches the end of its downward movement, the cam projection 20 engages the knock-off dog 19 and pushes the rod away from the 7 adjacent side frame 2 so as to move the seat 12 out of alignment with the frictionless rest or support afforded by the roller 11, the yoke 21 then being drawn outagainst the force of the spring 28., The rod now drops until the seat 12 of the dog 13 is arrested by the cushion stop 30 and this downward movement of the rod causes the rolls 4 to make contact again with the opposite faces of the board 5 to lift the hammer. The raising and dropping of hammer thus takes place so long as the treadle 41 is depressed and can be stopped by releasing pedal 41. 7

By this design of the drop hammer, fricaamsamo ti'on-and wear'areiminimized, whileany necessary repairs are rendered easy :toanakei The friction issgreatly lessened hy the anti- Erictiiona'l irolilers Jill and I22.

.As the .rodreac'h'es the lower limit of its movement, it does not stop abruptly, because ofithe efliect provided by the pad 30 and the spring This cushioning oi the fall of the rod 8 causes the rolls to engage the opposite t-aces oi the board 5 gradually instead 0 f with an im act or blow. If the rolls 4 were permitted :toengage the board 5 with a pronounced impact, the board 5 would soon be-destroyed, first by the d rect effect of the blow and next because the blow or impact would cause the roll ls "to rebound from the board '5 and slip, thus grindi-ng'or scoring the two 'taces of the board.

A itur 'thor advantage of the construction above described resides in thefact that the knock-off or outward movement of the rod 8 toenaibletheseat 12 to slip past the roller 1]. can be timed so that the rolls 4 will again engage with the board 5 at "the instant the hammer strikes the anvil '1 and rebounds; This enables the hammer to be lifted with a minimum ezqaenditure of power, because the inertia of the hammer -6 does not have to be first overcome. The initial upward impulse is provided by the rebound oi the mm or hammer and the rolls 4 merely continue the elevation of the hammer '6 thus commenced. If this timing were difierent, the hammer would have to be s'tartedu'pward from astate ofrestand more powerto lift the hammer at the end of each working stroke would be needed. The hammer is thus not only efiiciently control-led, but isalso quite economical and capableof a much longer period of service.

Attention is directed to the fact that when the dog 13 is*initslowered position the side iacethereo'f engages against the roller 11 and is held 'tliereaga-ins't by the action of the spring associated with yoke 21. Thus, frictional resistance to movement of the rodupwardly is reduced.

Attention is further directed to the fact that the roller -11 provides an efiective upwardly and inwardly inclined surface, in ad- Vance-of the seat proper, against which the lower-edge of the dog may engage andover which this edge may ride permitting the dog to come smoothly to its seat. In the ordinary construction where abrupt faces are provided for the seat and dog associated. therewith, it

is necessary that the rod be elevated sunciently to provide clearance betweenthese faces, which means that the dog must be elevated above its seat, with the result that the dog slams downwardly on the seat and these twozsurfaces become rapidly worn, requiring constant adjustment and soon being destroyed. In the present construction it is not necessary that the upward movement of the mod carry the dog ltO ifihe upper level of the surface zoztithefseat 4501' with the provision of the ca'm If-ace included in fthe mol- 'ler 1' 1,

' spring 2 7 operating through the yoke 21 "upon Asa safety IHGQSU-PQlillG tread-11241 is preiferably :so conneoted to shaft 42 that it may be swung upwardly thereabou t from its 'operati-ve positionillustrated in solid lines in 2 to 'a dotted position as ildustra ted in this figure thereby placing it in such a Epo:

si tion that it is impossible tfor the operator to accidently initiate operation of the harm mer.

1 claim: y

1. A- board hammer comprising a -ram to be lifted and dropped, a frontgrod to :control the ram, means for enabling the rod-to "be raised and lowered according to the position o-f-the ram, a stop for-"the rod when flowered,

aflsupport for the rod when raised, and-"yield able means mounted on the rodtoengage the stop when the rod is adjacent theend' -o f fits downward movement, and the support when the rod is raised.

2. Aboardhammer comprising a ramtobe lifted and dropped, a'front rod tocon'tr'ol the ram, means for enabling the 'front rod to be raised and lowered according to the movemen t of the ram, :a-n anti-friction "roller mounted in stationary position, an element carried by the rod to upon said roller when the rod is in raisedposition and engage against 'the roller as the'rod is raised and lowered. o

' '3. Aboard hammer comprising a to be li fited and droppecha front rod tocontrol the movem'entiof the ram, means'ior enabling the rod to be raised and lowered according 'to'the position of the rain," a stop adjacent saidro'd, acilamp 'on said rod, :a dog on-the rod yielda bly secured to the clamp to engage the stop when the rod-is ini ts lowered positlon. g r

4. A board hammer .comprlsmg-a ram to be lii'rtedand dropped, a fron't'rrod' to be raised and lowered to contro'l the ram, means for enablmgthe rod to T186 and fZUIllfHJCCOIdIHg to the position of the ram, a clamp fixed to said rod, a dog on said rod, bolts carryin springs for yielda bly connec tingthe dog an clamp together, and a "fixed stop toabe engaged by the do g "when the rod is adjacent-its {lowermost position. 3

5. "A board hammercoin-pr ising a 'ram to be lifted'and dropped, a front rod to control are the ram, means for shifting said rod according to the position of the ram, a roller mounted in stationary position adjacent the rod, a clamp fixed to the rod, a dog yieldably connected to the clamp, a seat carried by the dog to rest upon said roller, arresting means to be engaged by the seat when the rod is shifted to disengage the seat from the roller to liberate the rod for movement, a yieldably mounted yoke, and a roller in said yoke to engage the rod and tending to hold the rod to keep said seat in line with said anti-friction roller.

7 A board hammer comprising a ram to be lifted and dropped, a front rod, means 'for causing said rod to rise and fall'according to the position of the ram, an anti-frictional support, an element mounted on said rod to engage the support when the rod is in raised position, and means constantly urging the rod toward the support, the support having an upwardly and inwardly inclined face at the junction of its upper and its rod confronting sides. 7

8. A board hammer comprising a ram to be lifted and dropped, a front rod, means for causing said rod to rise and fall according to the position of the ram, and anti-frictional support, and an element mounted on said rod to engage the support when the rod is in raised position, said element being yieldably mounted upon the rod.

9. A board hammer comprising a ram to be lifted and dropped, a front rod to control the ram, means for enabling the rod to be raised and lowered according to the position of the ram, a stop, a support vertically placed above the stop andyieldable means mounted on the rod to alternately engage the support and stop, the support having an upwardly and inwardly inclined face at the function of its rod confronting and upper faces. for co action with said yieldable means.

10. A board hammer comprising a ram to be lifted and dropped, a front rod to control the ram, means for enabling the front rod to be raised and lowered according to the movement of the ram, an anti-friction roller mounted in stationary position, an element carried by the rod to rest on said roller when the rod is in raised position, and means constantly urging the rod towards said roller to maintain said element against the roller as the rod is raised and lowered. 11. A board hammer comprising a ram to be lifted and dropped, a front rod to control.

the ram, means for enabling the rod to be raised and lowered according-to the position of the ram, a stop for the rod, yieldable means mounted on the rod to engage the stop when the rod is adjacent the end of its downward movement, an anti-friction roller above'the stop with which said yieldable means en gages. when the front rod is being raised and upon which the yieldable member seats when the rod is completely raised and means constantly urging the rod toward said roller;

12. A board drop hammer comprising a ram to be lifted and dropped, a front rod to control the movement of the ram, means for enabling the rod to be raised and lowered according to the position of the ram, a stop, a support spaced from thestop, a yieldable member to alternately engage the stop and supportand means adjustably and removabliy connecting said yieldable member to the ro 13. A board drop hammer comprising a ram to belifted and dropped, a front rod to control the movementof the ram, means for shifting the rod according to the position of the ram, a support for the rod when in its uppermost position having vertical and horizontal faces, a roller disposed at the junction of the faces and projecting beyond each thereof, a member secured to the rod seating upon said roller when the rod is raised and means holding said member in engagement with the roller as the rod is lowered.

14. A board drop hammer comprising a.

ram to be lifted and dropped, a front rod, means for causing said rod to raise operated by the ram, a support for the rod, a member on the rod adapted to engage the support when the rod is raised to maintain the rod in raised position, the first-named means elevating the rodthrough a distance insufiicient to cause supporting engagement ofsaid member and means including an inclined face on one of said support and member for further elevating the rod to cause the member to come into supporting engagement with said support, the member being yieldably mounted on the rod.

15. A board drop hammer comprising a ram to be lifted and dropped,'a front rod, means for causing said rod to raise operated by the ram, a support for the rod, a member on the rod adapted to engage the support member and means including a roller on one. of said support and member for further elevating the rod to cause the member'to come into supporting engagement with said support, the member being yieldably mounted on the rod; 7 p HOWARD TERHUNE. 

